JAHW050F1-S Lineage Power, JAHW050F1-S Datasheet - Page 12

• Manufacturer Part Number: JAHW050F1-S
• Manufacturer: Lineage Power

JAHW050F-S and JAHW075F-S Power Modules; dc-dc Converters:
36 Vdc to 75 Vdc Input, 3.3 Vdc Output; 50 W to 75 W
Thermal Considerations
Introduction
Proper cooling can be verified by measuring the tem-
perature. Peak temperature (T
indicated in Figure 22.
Figure 22. Temperature Measurement Location
12
12
THERMOCOUPLE
CENTER OF THE
OPTOCOUPLER
IS ATTACHED
TO THE TOP
Figure 21. Worst Orientation (Top View)
HERE
(Bottom View)
(continued)
C
) occurs at the position
(continued)
AIRFLOW
8-3020 (F)
8-3021 (F)
The temperature at this location should not exceed
100 °C. The output power of the module should not
exceed the rated power for the module as listed in the
Ordering Information table.
Although the maximum temperature of the power mod-
ules is 100 °C, you can limit this temperature to a lower
value for extremely high reliability.
Heat Transfer
Increasing airflow over the module enhances the heat
transfer via convection. Figures 23 and 25 show the
maximum power that can be dissipated by the
JAHW050F-S module without exceeding the maximum
temperature versus local ambient temperature (T
natural convection through 3 m/s (600 ft./min.) for the
best and worst orientation, respectively. Figures 24 and
26 show the maximum power that can be dissipated by
the JAHW075F-S without exceeding the maximum
temperature versus local ambient temperature (T
natural convection through 3 m/s (600 ft./min.) for best
and worst orientation, respectively.
Note that the natural convection condition was mea-
sured at 0.05 m/s to 0.1 m/s (10 ft./min. to 20 ft./min.);
however, systems in which these power modules may
be used typically generate natural convection airflow
rates of 0.3 m/s (60 ft./min.) due to other heat dissipat-
ing components in the system. The use of Figures 23
and 25 is shown in the following example.
Example
What is the minimum airflow necessary for a
JAHW050F-S operating at V
of 10 A, and a maximum ambient temperature of
55 °C?
Solution
Given: V
Determine P
Determine airflow (v) (Use Figures 23 and 25.):
I
T
P
v = nat. conv. (Best orientation)
v = 0.5 m/s (100 ft./min.) (Worst orientation)
O
A
I
D
= 10 A
= 75 V
= 55 °C
= 6 W
D
(Use Figure 27.):
I
= 75 V, an output current
Tyco Electronics Corp.
November 2000
Data Sheet
A
A
) for
) for